Polluted smog covers Pakistan's city of Lahore

Motorists drive through a road close to historical Badshahi mosque while dense smog engulf the neighborhood of Lahore, Pakistan, Saturday, Nov. 5, 2016. Thick smog has engulfed several cities in central Pakistan for a few days, causing, breathing problems, road accidents and disruption of flight and train scheduled as well as the closure of the sections of the main motorways. (AP Photo/K.M. Chaudary)
(The Associated Press)

Birds sit on a tree in the dense smog in Lahore, Pakistan, Saturday, Nov. 5, 2016. Thick smog has engulfed several cities in central Pakistan for a few days, causing, breathing problems, road accidents and disruption of flight and train scheduled as well as the closure of the sections of the main motorways. (AP Photo/K.M. Chaudary)
(The Associated Press)

A Pakistan rides his donkey-cart though a road while dense smog engulf the neighborhood of Lahore, Pakistan, Saturday, Nov. 5, 2016. Thick smog has engulfed several cities in central Pakistan for few days, causing, breathing problems, road accidents and disruption of flight and train scheduled as well as the closure of the sections of the main motorways. (AP Photo/K.M. Chaudary)
(The Associated Press)

Mohammad Hanif said Saturday that several cities in eastern Pakistan have been engulfed in haze since earlier this week. He said the smog has caused irritation in residents' eyes and an increase in respiratory-related health problems.